In a geodatabase, a mechanism for optimizing access to data based on the spatial column of the business table.

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33
votes
2answers
4k views

Acquiring ArcGIS-like speed in Postgis

I have been using Postgis 2.0 for 3/4 of a year now and while I really enjoy using it, excessive query processing time has rendered it basically unusable for my use case. I tend to do heavy ...
11
votes
5answers
2k views

Speeding up OpenStreetMap PostGIS querying

I have OpenStreetMap data for the Netherlands loaded into a PostGIS database (PostgreSQL 8.3 / PostGIS 1.3.3) using the osmosis schema. This means all tags are stored in a hstore field. In addition to ...
10
votes
3answers
947 views

How to speed up queries for raster databases?

I have a raster database in postgresql/postgis with these columns: (ID, rast, data_of_data). 'rast' is the column that has raster files in WKT format. An example query to find the DN value of a ...
10
votes
3answers
2k views

optimize nearest neighbor query on 70 million extremely high density spatial point cloud on SQL Server 2008

I have about 75 million records in a SQL Server 2008 R2 Express database. Each is a lat long corresponding to some value. The table has geography column. I am trying to find one nearest neighbor for a ...
8
votes
2answers
534 views

PostGIS Intermittent INDEX Performance

I have a table containing approximately 55 million data points ( point is a geometry with SRID 4326 ) and for my query I need to join this to an area table ( currently have ~1800 areas ) which ...
7
votes
2answers
299 views

Basics about Spatial Indexes

I was asking on a forum if it could be a good idea to create spatial indexes on subsets of a table when your application display on map only those subsets and never the entire table. I was asking ...
7
votes
3answers
3k views

Poor Performance when using Spatial Indexes in MySQL

Re-post of a question asked on Stack Overflow when it was suggested this would be a better forum. I'm trying a little experiment at pushing a data set which is not geo-spatial but fits it quite well ...
5
votes
2answers
681 views

How does a quad-tree cope with very large objects?

If I use a quad-tree to index my map data, how does it cope with a road that goes from one end of the map to the other? What other sort of indexes should I consider to get round this problem?
5
votes
3answers
377 views

Trying to combine nearby points into a polygon

We have collected millions of cell phone strength readings. I am trying to group points of the same strenght that are within a distance of each other in to a polygon. I asked on the postgis mailing ...
5
votes
1answer
234 views

Is it possible that a good spatial index just cannot be made?

I have about 6 million rows with geography spatial features - they are all 1000 meter radius hexagons all over the US. There are a couple hundred thousand that would have been NULL, which I updated ...
5
votes
1answer
778 views

How to speed up an st_intersects() query?

I have a "huge" spatial database: 72GB, 200 millions documents with geometries (points) I have a GIST index on the geometries the database: CREATE TABLE resources ( id bigint NOT NULL, accuracy ...
4
votes
3answers
712 views

Create Spatial Index in PostGIS on an entire Schema

I have loaded a number of shapefiles using SPIT (QGIS plugin) to my PostGIS database. These layers did not have a Spatial Index created upon loading. I am wondering if there is a way to create a ...
4
votes
2answers
599 views

How to delete a broken index in SpatiaLite?

I managed to screw up an index in my SpatiaLite database. The index was created using spatialite-gui. In the meantime, I deleted the original table and three out of four index files: ...
4
votes
1answer
137 views

Understanding the Use of Spatial Indexes

I'm having trouble understanding the use of spatial indexes with RTree. Example: I have 300 buffered points, and I need to know each buffer's intersection area with a polygon shapefile. The polygon ...
4
votes
3answers
3k views

How to properly utilize DWITHIN Spatial Filter in OpenLayers

Given the following code: var points = []; points.push(new OpenLayers.Geometry.Point(-110, 38)); points.push(new OpenLayers.Geometry.Point(-108, 40)); var lineString = ...
4
votes
1answer
259 views

Spatial index vs two coordinates indexes

I have a table with two columns: latitude and longitude. I want to get all objects inside a "rectangular" (well, rectangular in a lat/lon coordinate metric) bounding box: min-max latitude and min-max ...
4
votes
1answer
513 views

Shorter Version of this SpatiaLite Query

I've been doing some spatial queries using spatialite, and they're large enough that a spatial index becomes a must. An example of using an index is given in the tutorial spatialite> SELECT ...
4
votes
2answers
395 views

Spatial Indexes on OS MasterMap Data

What are the optimal settings for setting up a SQL Server 2008 Spatial database with full UK OS MasterMap data in? Seperate tables for the different feature types, or a single table with everything ...
3
votes
2answers
3k views

How can I use R-Tree to find points within a distance in Spatialite?

Create a table with 3D points: create table points (coords pointz); select CreateSpatialIndex('points', 'coords'); Insert 13k rows: insert into points values (geometryfromtext('pointz(...)')) Do ...
3
votes
1answer
63 views

Does QGIS automatically use spatialite spatial indexes?

When you write a query in spatialite you have to manually join your query to the spatial index for that index to be used to speed up the query. When QGIS displays data does it take advantage of any ...
3
votes
1answer
1k views

SQL Server 2008 Spatial Index Nearest Neighbour

I am trying to query geopoints for nearest neighbour, Whether I use spatial index or not, I always get similar times and it takes about 6 seconds. How can I speed this query up? Here is my query: ...
3
votes
1answer
2k views

How do I create a functional spatial index of an ST_Geometry Feature Class in Oracle/SDE?

Copied an SDE feature class (with blob(sdebinary(?) geom) into the same SDE GDB (Oracle 11g/SDE 9.3.1) but with the ST_geometry configuration keyword. I can see that the feature class was created, ...
3
votes
1answer
57 views

How to quickly extend PostGIS's R-Tree implementation?

I am working on a problem where along with data points location, I also have information about the connectivity between points.(Think a graph of points, where an edge denotes some relationship) My ...
3
votes
1answer
336 views

For which operations a PostGIS Geography index is useful?

I need to do KNN- and within-region queries for POI data. I store the POI locations in a geography column. Since I understand that ST_DISTANCE doesn't use the geography index, I added a geometry index ...
3
votes
0answers
172 views

Are there trade offs between using a geohash vs using a quadkey as a spatial index?

QuadKey Bing Maps uses a quadkey structure for their tiling scheme. Here is an overview of the concept http://msdn.microsoft.com/en-us/library/bb259689.aspx. GeoHash A geohash seems to be the more ...
3
votes
0answers
148 views

sql server spatial index performance

I have a table with around 2 million records in it. I create a spatial index, using the defaults other than the bounding box. I've been noticing that some queries are extremely fast, and some are ...
3
votes
0answers
247 views

Creating a ShapeFile spatial index programmatically in .Net

I am creating a shapefile programmatically using DotSpatial using the following example syntax / pseudo code FeatureSet features = new FeatureSet(DotSpatial.Topology.FeatureType.Polygon); ...
2
votes
2answers
88 views

Does PostGIS have separate implementation of GiST index from PostgreSQL?

I want to know if PostGIS has a separate implementation of GIST index or it reuses the GIST index implementation provided by Postgresql?
2
votes
3answers
596 views

how to create RTree index on LineString geometry

I'm working with NTS(NetTopologySuite), then I get some geometries with type of LineString, and I want to create the IntervalRTree Index on them. Here are some codes: ...
2
votes
2answers
282 views

IFeatureIndex2.Index Performance Issues ArcObjects

I have a large number of polygon features in a personal geodatabase featureclass. I would like to find the nearest polygon for several points inside an area of interest(the red area in figure). I ...
2
votes
1answer
247 views

Why doesn't PostGIS use gist index when doing a ST_DUMP(ST_UNION)?

My query: DROP TABLE IF EXISTS tmp; CREATE TEMP TABLE tmp AS SELECT *, ST_BUFFER(the_geom::GEOGRAPHY, 3000)::GEOMETRY AS buffer FROM af_modis_master LIMIT 20000; CREATE INDEX idx_tmp_the_geom ON tmp ...
2
votes
2answers
1k views

Spatial index to speed up the query

I have spatial table in PostgreSQL 9.2 / postgis 2.0 that I have to extract some information from it. But my query is hopelessly slow. How could I make use of spatial index to improve the performance ...
2
votes
2answers
43 views

Geary's index of spatial autocorrelation

Does anyone knows If there is a way to calculate Geary's index of spatial autocorrelation on open source gis?
2
votes
1answer
228 views

How do you build a MongoDB spatial index for GeoJSON geometry?

I'm attempting to build a spatial index on a collection of features that I created from: ogr2ogr -f GeoJSON out.json ... and then imported into MongoDB (2.6.1). When I attempt to build a spatial ...
2
votes
1answer
214 views

ST_Intersects() in WHERE clause misses results

I have a table with a lot of geographical objects like countries, cities or points inside the cities. For instance # SELECT id, ST_AsText(location) FROM brace_brace WHERE id IN (3, 42); id | ...
2
votes
1answer
773 views

rtree python polygon index

Sorry for a very basic questions about rtree. I would like to check whether the point is inside the polygon and the distance (point to the nearest point in polygon) as well. I was thinking about ...
2
votes
1answer
40 views

What are the PostGIS Raster Constraints used for?

My question is quite basic, but I have not found a simple explanation of why raster constraints are useful. I have worked with rasters in PostGIS for a while but only recently I realized that I do ...
2
votes
1answer
188 views

Fast zipcode detection from latitude/longitude

I need a way to get the zipcode of a lat/long pair fast (<10 ms), and at a high rate (thousands of qps) I've loaded a shapefile from the US Census Bureau into a mysql database with spatial ...
2
votes
1answer
97 views

Fastest strategy for proximity searches in SQL Server 2012

This is my very first question here, so bear with me! I'm implementing a back end for a mobile app which will have to do proximity searches to find nearby POIs (points os interest). I know it's a ...
2
votes
2answers
807 views

Is ArcMap 10.0 Query Layer passing invalid SQL to Oracle 11gR2?

In two different environments I'm having trouble using ArcMap 10.0 Query Layers to view SDO_GEOMETRY (point) data in Oracle 11.2. This suggests I'm doing something wrong... Points are in Oracle ...
2
votes
0answers
31 views

Match housenumbers on buildings (special case of point-in-polygon-test)

Task with example I'm working with geodata (country-size) from openstreetmap. Buildings are often polygons without housenumbers and a single point with the housenumber is placed within the polygon of ...
2
votes
0answers
24 views

Cannot see the shapes in arccatalog or arcmap after creating spatial indexes

I created a spatial index on a feature class, but when i try to load it in arcmap, i cannot see the shapes. When i remove the spatial index, i can see the shapes in arcmap/arccatalog.
2
votes
0answers
254 views

How do you view the current spatial index grid size for a file geodatabase feature class?

I am receiving an "The spatial index grid size is invalid." error during a copy/paste of polygon features in ArcMap and I successfully corrected it with AddSpatialIndex. But in an effort to figure out ...
2
votes
1answer
192 views

3D KNN index in PostGIS

I am looking for a way to do fast KNN queries on a dataset of 10+ million 3D points (and growing). I was hoping PostGIS would do the trick with its new <-> and <#> operators, but they don't seem ...
2
votes
0answers
180 views

How could I make this PostGIS query run faster?

SELECT st_band(rast, 1), st_width(rast), st_height(rast), st_bandpixeltype(rast, 1), st_bandnodatavalue(rast, 1), st_scalex(rast), st_scaley(rast), st_upperleftx(rast), st_upperlefty(rast) FROM ...
1
vote
3answers
1k views

C# library for bounds based geometry search

I am searching for C# library which has code that builds spatial index in memory based on geometry bounds and enables fast searching for all geometry inside given bounds. I prefer free library.
1
vote
2answers
373 views

How to speed up spatialite-query using spatialindex?

I have got 2 tables, one of type LineLayer called strlayer, the other one is a PolygonLayer called blayer. The LineLayer contains two rows called fromBland and toBland that should be filled with an ...
1
vote
1answer
55 views

Geoserver WFS features query inaccurate using SQL Server Backend with spatial index

I´m using Geoserver to query features through WFS in an Web Application with Openlayers as client. The queried layer is using SQL Server as backend storage. When applying a spatial index to the ...
1
vote
2answers
204 views

How to work with the STRtree Index when object in the index change it's position?

I'm work with the NTS(NetTopologySuite), I get large amounts of Point geometries, for fast querying the point object, I make the STRtree Index like this, STRtree tree = new STRtree(); foreach (var p ...
1
vote
1answer
33 views

Index to speed up ST_HausdorffDistance?

When comparing similarity of linestrings with ST_HausdorffDistance (or another type of similarity function), is there a way to use an index to speed up the search for similar linestrings?